Great part but I made some modifications on for the second attempt after cars kept getting caught on the corners.
Hobby King PLA
Using Cura to slice and Fusion360 to edit. 3 walls, 3 top layers, 3 bottom layers, print speed 40mm/s (slightly higher for inner wall but lower for outer wall), roof for the support and also an extra skin layer (makes support interface smoother). 200°C hot end and 65° bed (glass bed).
I smoothed the corners to help keep the cars from colliding with the sides and also levelled off the middle. I know there are many slight variations of this track (I live in UK and our track already has two different types with tiny differences in the fastenings) and think the connections could be wiggled over a bit for a better fit but overall great part, nice work deadcat